High pressure well packer



y 1966 H. E. M GOWEN, JR 3,249,149

HIGH PRESSURE WELL PACKER 2 Sheets-Sheet 1 Filed Jan. 2, 1964 A. f.Mc'owen, z/r.

INVENTOR BY g L be? ATTORNEY May 3, 1966 H. E. M GOWEN, JR 3,249,149

HIGH PRESSURE WELL PAGKER Filed Jan. 2, 1964 2 Sheets-Sheet 2 Mc60m/a/7,Jr.

INVENTOR.

BY QC (LI/m ATTORNEY United States Patent 3,249,149 HIGH PRESSURE WELLPACKER Harold E. McGowen, Jr., Houston, Tex., assignor to Camco,Incorporated, Houston, Tex., a corporation of Texas Filed Jan. 2, 1964,Ser. No. 335,170 7 Claims. (Cl. 166-120) This invention relates to wellpackers for incorporation in a production tubing string for loweringwithin a well bore to a given down-hole position at which the packirrgseal is deformed to bear on the bore wall or its casing liner so as tofill and block the adjacent annular space exteriorly of the'tubingstring and thereby close off from one another the annular space aboveand the annular space below the packer seal. More particularly, theinvention relates to an improved interlock joining packer components tosecurely resist displacement from packer setting relationship.

An object of the invention is to provide a hydraulically actuated latchwhich comes into play automatically and secures the set packer assemblyagainst unintentional release.

A further object is to combine a releasable latch element with othercomponents of the packer assemblywhose parts are retracted andineffective initialy and during tubing run-in travel through the wellhole and until the tubing string is properly manipulated to conditionthe parts for and to effect the packer setting operation andcoincidently therewith to harness well fluid pressure differentialacross the packer for both actuating holddown slips into clutchingengagement with the casing and for projecting latch dogs forinterlocking parts of the packer assembly against release.

Another object is to provide a fluid passageway inside the packerassembly and across the packing collar seal through which pressures areequalized prior to packer release and which passageway at its upper endis initially partly in vertical section and partly in elevation of thepacker assembly in the initial running-in relationship.

In the drawing, a well casing 1 is shown as having fitted thereto apacker assembly including an elongated mandrel 2 surrounding a full openbore and arranged for coupling connection at opposite ends with adjacentsections of a well tubing string 3 so as to constitute a part of thetubing string. In sleeved embracement on the lower part of the mandrel 2and in end to end succession are tubular packing components comprising abottom slip retainer cage 4, a slip expander 5 and a packing collarmandrel or body assembly 6.

Near its lower end the mandrel 2 is thickened by fitting and weldingthereto an external tube 7 having a pair of diametrically oppositeJ-slots 8 of which the longer legs extend upwardly and terminate inV-shaped months at the top edge of the tube 7. Fitted within the-V-shaped mouths are similarly shaped bearing teeth depending from apressure thrust distributing ring 10', as best seen in FIG. 2C. Thisring 10 is for abutment with the underside of a pick-up shoulder orlaterally projecting annular rib 11 at the lower terminal of a tubularsleeve 12 which is part of the packing collar mandrel 6. In

3,249,149 Patented May 3, 1966 turn, the rib 11 is for pickup andseating suspension of an internal ledge of a stop abutment ring 13fixedly threaded on the upper end of the tubular slip expander 5.

The tubular expander 5 extends inside the cage 4 and terminatesdownwardly in a tapered or conical outer face St: for wedge bearing onmating tapered faces of a set of segmental slips 14 having downwardlyfacing wickers exteriorly thereof and being laterally projectablethrough cage windows and retained therein by the usual marginal lips(not shown) which underlie adjacent edges of the cage wall. Similarretaining lips locate casing enga'geable drag shoes or friction blocks15 within the cage window. Each block is biased outwardly by a set ofupper and lower coil springs 16--16 and the upper coil spring seatsinwardly against a dependenttail or tab 17 on the adjoining slip 14 andresiliently urges the slip inwardly. Both the slip tail 17 and the lowerspring 16 bear on an upstanding tubular wall 18 of a retainer ring 19which is inserted within and closes the bottom of the outer wall of thecage 4 and is secured thereto by one or more screws 19a. Thus thesprings 1616 exert no force on the mandrel 2 which has a free slidingfit on the retainer ring 19. Inwardly projecting and outwardly headedslip clutch pins 20 are fitted to counterbored openings of the ring 19and are held by an overlapping wall portion of the cage 4.

Bearing downwardly on the abutment ring 13 of the expander 5 is a packercollar 21 of rubber or other suitable elastic deforming material snuglyembraced on the sleeve 12 of the mandrel 6 which, for convenience ofmanufacture and assembly, also includes a tubular body 22 and a terminalextension tube 23 threaded'togetherin end to end succession. The wallthickness of the body 22 and of the unstressed packing collar 21, asseen in FIG. 2B, are substantially the same and the bottom end face ofthe body 22 is for downward force transmission abutment with the packercollar, preferably through a deformable metal washer 24. packer mandrelsections comprising the sleeve 12 and the body 22 somewhat exceed theoutside diameter of the tubing mandrel 2 and the intervening clearanceconstitutes an internal fluid passageway 25 across the packer collar andhas its opposite ends open to the exterior of the packer assembly whenthe packer collar is not in packing position. The lower passagewayopening is through one or more radially aligned holes 26 in the bottomportion of the sleeve 12 and the surrounding abutment ring 13 of theexpander tube. The upper opening is through the top of the bodyextension tube 23.

Drilled through the wall of the body 22 is a group of radial openingsproviding slide piston receiving chambers 28a for inward communicationWith the internal passageway 25. Peripherally sealed pistons,constituting casing engageable hold-down slips 28, are retained withinthe chambers by narow straps 29 secured within vertical peripheral slotsin the body 22 in bridging relation with the outer faces of the pistonswhich are grooved to straddle the retainer straps 29 and carry upwardlyfacing wickers for clutched engagement with the 'well casing. Bellevillesprings 30 interposed between the retainer straps 29 and the pistonsresiliently urge the pistons inwardly in the absence of differentialpressures on oppositely facing piston surfaces. 9

Above the hold-down piston chambers, the internal diameter of the body22 is stepped outwardly and is machined to a smooth cylindrical sealingsurface 31. This cylindrical surface terminates upwardly in a beveledguiding edge and a flat abutment shoulder 32. Above the shoulder 32, thebody extension 23 is formed with an internal keeper groove 33 whichterminates upwardly in an inwardly inclined shoulder 34. These internalsurface formations at the top of the body 22, and as better indi-Internal diameters of the i cated by their dotted line showing in FIG.2A, are for reception and mating co-operation with complementary surfaceformations carried by the head or coupling collar 35 at the upper end ofthe tubing string mandrel 2. Below its internally threaded uppercoupling portion, the collar or head 35 has a dependent skirt 36 inannular clearance fitment with the mandrel 2 to afford a fluidpassageway 37. Externally, the skirt 36 is of stepped diameter and adownwardly facing shoulder 38 separates the lower diameter portion fromthe larger upper diameter portion. Below the shoulder 38, the smallerdiameter portion of the skirt is machined true to fit closely to themachined cylindrical surface 31 of the body 22 for interfitted valvingco-operation in sealing the upper end of the passageway 25 when thetubing string is telescoped downwardly into the body 22. Insuranceagainst leakage is afforded by interposing a seal, such as a pliablerubber gasket ring 39, between the surfaces and pocketing the samewithin a peripheral groove in the skirt 36.

Through the upper wall portion of the skirt 36 are one or more lateralopenings or chambers 40a communicating inwardly with the internalclearance passage 27 and slidably receiving peripherally sealed pistons40. In its outer face, each piston has a horizontally disposed andupwardly and inwardly inclined shoulder 41 between vertically offsetouter face portions. The piston provides a projectable latch dog forprojection into the keeper groove 33' and the shoulder 41 is for seatingengagement with the internal shoulder 34. At its outer lower corner,

' each latch dog or piston 40 has a re-entrant groove and fits an upwardextension into the piston opening of a retainer ring 42 sleeved on theskirt 36. This interfitment retains the latch dog piston 40 againstrotation for retaining the shoulder 41 in horizontal position and alsoprevents drop-out of the latch dog piston.

When a packer assembly as described is to be set within a well bore, thepacker will be incorporated in a production tubing string and lowered toa desired downhole location. Packer external diameter can be onlyslightly less than the liner casing internal diameter since all packercomponents except the friction blocks will be initially contracted andcentered by the friction blocks out of wear contact with the casingwall. During downward travel, the lower clutch pins located within theshort legs of the J-slots, transmit the travel force and pull down theslip cage with the friction blocks 15 dragging along on the casing wall.When the packer is to be set, descent of the tubing string isinterrupted and the tubing string is elevated and rotated slightlythrough an angular distance to swing the J-slots '8 relative to theclutch pins 20 for aligning the long reaches of the J-slots with thepin. Upon such alignment and with the frictional contact against thecasing wall of the friction blocks 15 for resisting movement of the cage4, the tubing string can be lowered with the mandrel sliding freelythrough the external packer component to effect entrance of the mandrelhead or collar into the socket formation of the body 22. After theshoulder 38 of the tubing mandrel is seated on the shoulder 32 of thepacker body 22, further downward force is transmitted from the tubingstring to set the lower slips 14 and then expand the packer collar 21into packolf relation with the annular space surrounding the tubingstring. At the same time, the internal passage is closed at its upperend at the valving surfaces 31 and 39. Increase of fluid pressure belowthe expanded packer as can be controlled by regulation of pressurewithin the bottom opening tubing string, will become active through thepassageways 25 and 37 and within the piston chambers 28a and a behindthe hold-down slips 23 and the latching pistons 40 for their outwardprojection. Such pressure maintains the hold-down slips in tightclutching contact with the casing to resist displacement forces andalso, by reason of latching piston and keeper interengagement, maintainsthe parts against displacement to packer release relationship.

Should packer release be desired at some later time, then a short upwardjar or pull transmitted through the tubing string, with or withoutregulating control of downhole pressure, will bring the inclinedsurfaces of the shoulders 41 and 34 on the latch piston 40 and keepergroove into a camming relationship for forced piston retraction andrelease of the safety interlock between the tubing mandrel 2 and thebody 22 of the packer mandrel 6. Additional tubing string elevation thenopens the top of the internal passage 25 for equilization of pressuresacross the packing, and whereupon the hold-down slips 28 will be springretracted and permit elastic recovery of the packing collar 21. As soonas tubing string elevation brings the flared mouths at the top of the.T-grooves 8 into engagement with the complementary teeth'of the bearingring 10, the bearing ring 10 will make pickup engagement with the bottomrib 11 of the packer mandrel 12 and raise the rib 11 into abutment withthe ring 13 of the expander tube 5 for pulling the latter away fromwedging relationv with the bottom slip 14, which then moves to retractedposition under the force of the spring 16. Thereafter, the bottoms ofthe J-slots will pick up the pins 20 and transmit upward travel of thetubing string to the cage and friction block 15. At this time the partsof the packer assembly will be in their positions of initialrelationship and the packer can be reset in any desired position withinthe well casing or can be completely withdrawn to the surface andremoved from the well.

While the foregoing description has been limited to a single embodiment,it is to be understood that the invention is capable of variousmodifications as come within the scope of the appended claims.

What is claimed is:

1. In a well packer assembly, a deformable packing collar, a lowercollar stop abutment and slip unit, an upper collar abutment and slipunit having a tubular sleeve surrounded by the collar and terminatedabove the collar in an internal valve seat and a latch dog receivinginternal groove, a fluid passage extending through said valve seat andthe tubular sleeve to a point below the packer collar, a tubing stringmandrel projected through the tubular sleeve and reciprocable relativethereto and provided with an upper annular enlargement for movement withmandrel movement into and out of the internal valve seat and groove, abearing surface carried by the enlargement and movable into sealingengagement with said valve seat for blocking the upper end of said fluidpassage, a hydraulically actuated and laterally projectable latch dogcarried by the enlargement for alignment and reception within saidinternal groove and means active when the upper end of the fluid passageis blocked for communicatiing said fluid passage with and for projectionof said latch 2. In a well packer assembly having a lower slipsubassembly, a tubing string mandrel slidably projected through'the slipsubassembly, a packing collar mandrel sleeved on the tubing stringmandrel above said slip subassembly for relative mandrel reciprocation,a fluid passageway through the packing collar mandrel, mating sealingsurfaces on said mandrels arranged to be brought into seating contactone with the other at one limit of relative mandrel reciprocation forthereby closing the upper end of said fluid .passageway, a latch dogkeeper formation on one of said mandrels, a hydraulically actuated andlaterally projecta'ble latch dog positioned by the other mandrel foralignment with said keeper formation at said last mentioned limit ofmandrel repciprocation and means to direct actuating fluid from saidpassageway into latch dog projecting relation when said upper end of thepassageway is closed by seating contact of said sealing surfaces.

3. In a well packer assembly as in claim 2, said packing collar mandrelalso having hydraulically actuated holddown slip means in the upperportion thereof comprising chamber means communicating inwardly withsaid passageway and slip means slidably fitted to and outwardly closingthe chamber means for displacement laterally in response to differentialfluid pressures thereon.

4. In a Well packer assembly as in claim 2, one of said sealing surfacesand the keeper formation being in juxtaposed axially spaced apartrelation internally of the upper end of said packing collar mandrel andthe other of said sealing surfaces and the latch dog being carriedexternally of the tubing string mandrel and being positionable withrelative mandrel-travel into and out of nested relation with said upperend of the packing collar mandrel.

5. In a well packer assembly having a lower slip subassembly, a tubularmandrel slidably projected through the slip subassembly and adapted forconnection in and as a part of atu'bing string, a collar on said mandrelhaving a radially disposed chamber, a laterally projectable latch dogslidably fitted to the chamber and closing its outer end, a downwardlyopening fluid passageway leading upwardly through said collar andcommunicating with the inner end of the chamber, a downwardly facingshoulder on the collar separating the portion thereof containing saidchamber from a lower and smaller outside diameter," portion, aperipheral sealing surface on said lower and; smaller diameter portion,a packing collar supporting mandrel interposed between said shoulder andsaid slip subassembly and sleeved on said tubular mandrel for therelative mandrel reciprocation, said collar supporting mandrelterminating upwardly in a socket for nested reception of the collar onsaid tubular mandrel, an upwardly facing internal shoulder within thesocket, a latch dog keeper within the socket above said shoulder, asealing surface below the shoulder of an internal diameter to providesealing contact with said sealing surface on the collar and a fluidpassageway extending through the collar supporting mandrel andcommunicating the exterior thereof below its supported collar with saidsocket at the upper end thereof.

6. Ina well packer, a tubular mandrel for coupled connection in atubular string, a packer subassembly sli-dably sleeved on the mandreland comprised'of a deformable packing collar, casing engageable slipmechanism having an upwardly facing collar abutment stop, a downwardlyfacing pressure applying collar abutment having upwardly and downwardlyextending tubular portions embracing and radially spaced from themandrel to provide fluid flow clearance between opposite ends of thecollar, chambers in the upwardly extending tubular portion communicatingwith the flow clearance, projectable pistons in the chambers havingouter clutching faces for casing retention engagement, and an internalsocket formation at the upper end of said upward extension providing anannular sealing surface and a latch keeper groove above the sealingsurface, said tubular mandrel having a peripheral head above the packersubassembly for movement therewith into and out of nested relation withsaid socket, a peripheral sealing surface on said head to bear on theinternal sealing surface of the socket, a chamber in the head above itssealing surface, an outwardly projectable piston in the chamber toprovide a latch dog engageable with said keeper groove and a fluidpassageway in the head communicating said chamber with the flowclearance within the socket when the head is nested therein.

7. In a well packer, a tubular mandrel adapted for connection with atubing string and provided with a head thereon, a lower slip and stopunit surrounding the mandrel, a packer collar subassembly sleeved onsaid mandrel and provided with a deformable packing collar engageabledownwardly with said unit and an upwardly opening socket above thecollar to receive said head upon relative downward travel of the mandrelin a packer setting operation, a fluid passageway including said socketand extending through said subassembly for communicating the exteriorthereof beyond opposite ends of the collar, interfitting sealingsurfaces on the head and said socket active to close the upper end ofsaid passageway from the exterior of the subassembly about the collarwhen the head is received within the socket, a latch dog keeperinternally of the socket, a keeper engageable latch dog laterallyprojectably mounted in the head and means in the head for transmittingto said latch dog the fluid pressure within the upwardly sealedpassageway.

References Cited by the Examiner UNITED STATES PATENTS 2,409,812 10/1946Taylor et al 166130 3,008,523 11/1961 Clark et al 166129 3,112,79512/1963 Keithahn 166120 CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner.

2. IN A WELL PACKER ASSEMBLY HAVING A LOWER SLIP SUBASSEMBLY, A TUBINGSTRING MANDREL SLIDABLY PROJECTED THROUGH THE SLIP SUBASSEMBLY, APACKING COLLAR MANDREL SLEEVED ON THE TUBING STRING MANDREL ABOVE SAIDSLIP SUBASSEMBLY FOR RELATIVE MANDREL RECIPROCATION, A FLUID PASSAGEWAYTHROUGH THE PACKING COLLAR MANDREL, MATING SEALING SURFACES ON SAIDMANDRELS ARRANGED TO BE BROUGHT INTO SEATING CONTACT ONE WITH THE OTHERAT ONE LIMIT OF RELATIVE MANDREL RECIPROCATION FOR THEREBY CLOSING THEUPPER END OF SAID FLUID PASSAGEWAY, A LATCH DOG KEEPER FORMATION ON ONEOF SAID MANDRELS, A HYDRAULICALLY ACTUAATED AND LATERALLY PROJECTABLELATCH DOG POSITIONED BY THE OTHER MANDREL FOR ALIGNMENT WITH SAID KEEPERFORMATION AT SAID LAST MENTIONED LIMIT OF MANDREL RECIPROCATION ANDMEANS TO DIRECT ACTUATING FLUID FROM SAID PASSAGEWAY INTO LATCH DOGPROJECTING RELATION WHEN SAID UPPER END OF THE PASSAGEWAY IS CLOSED BYSEATING CONTACT OF SAID SEALING SURFACES.